1. Field of the Invention
The present invention relates to a method for manufacturing a multilayer ceramic capacitor, in which internal electrodes printed on each of a plurality of dielectric sheets have reduced thicknesses using an absorption member, thereby allowing the multilayer ceramic capacitor to have a high capacity and be minimized.
2. Description of the Related Art
A multilayer ceramic capacitor (hereinafter, referred to as a “MLCC”) is an electronic element serving to intercept a DC signal, bypass, and resonate frequency. In order to satisfy miniaturization and light-weight trends of electronic products, MLCCs have been increasingly used. Further, demand for MLCCs has increased according to digitization of electronic products and expansion of the mobile communication market.
Particularly, MLCCs having high stability and super-high capacity have been developed, and many methods for manufacturing the above MLCCs have been proposed. First, a method for increasing the number of dielectric layers having uniform thin thicknesses to be stacked in the same volume has been proposed. Further, a method for increasing the dielectric constant of dielectric powder has been proposed. Together with the above methods, methods for equalizing and reducing the thickness an electrode layer printed on each of the dielectric sheets have been developed.
In order to satisfy the high-capacity and miniaturization trends of a BaTiO3-group high-capacity MLCC, a technique for manufacturing a thin dielectric sheet having a reduced thickness less than approximately 1 μm has been developed. In case that an electrode layer is printed on the thin dielectric sheet by screen printing, the thickness of the electrode layer may be larger than that of the thin dielectric layer.
FIG. 1 is a sectional view illustrating a conventional process for forming electrodes on a dielectric sheet using screen printing. As shown in FIG. 1, a screen 30 provided with meshes in a designated number is prepared to print internal electrodes 20 on a dielectric sheet 10. A Cu or Ni paste 25 for forming the internal electrodes 20 is placed on the upper surface of the screen 30, and is squeezed using a squeezer 40. Through the above procedure, the internal electrodes 20 are printed on the dielectric sheet 10.
In the above-described screen printing, the thickness of the internal electrodes 20 formed on the dielectric sheet 10 is determined by adjusting the viscosity of the paste 25 or the number of the meshes of the screen 30. Since the adjustment of the viscosity of the paste and the number of the screen meshes are limited, it is difficult to thin the internal electrodes 20 in the same manner as the dielectric sheet 30.
In order to meet with the small-thickness trend of the dielectric sheet, the thickness of the internal electrodes must be reduced. Since the thickness of the internal electrodes is larger than the thickness of each of the dielectric sheets in the conventional multilayer ceramic capacitor, it is difficult to increase the number of the dielectric sheets to be stacked. Further, in case that an ultra-thin dielectric sheet is formed and internal electrodes are printed on the dielectric sheet, the thickness of the internal electrodes becomes larger than thickness of the dielectric sheet. Here, when a plurality of the dielectric sheets are stacked under pressure, the dielectric sheets are torn or the internal electrodes are short-circuited due to a difference of heights between the electrode and the dielectric sheet.